In the field of advertising there is a strong and marked division between permanent signs and temporary signs.
Permanent signs are generally relatively large objects and are fixed in position substantially permanent, e.g. for remaining in place for several years and sometimes up to several decades. Such signs are mounted to large counterweights. In view of the intended long periods of use, local governments, e.g. city councils or municipalities, tend to allow such signs sparingly and tend to have extensive procedures for obtaining a permit to place the sign. For economical exploitation of the sign prolonged contracts with advertisers may be required; an empty sign gives a poor impression to viewers and allowing an advertisement to be displayed for longer periods than initially agreed may reduce market value of advertising campaign and/or the sign operator. Permanent signs may be integrated in permanent objects such as divider cabinets for electrical or water mains supplies and/or public transport stop shelters.
Temporary signs provide the benefit of allowing the sign to be put up when required e.g. when a campaign is started and removed when the campaign is ended. Thus a certain surprise effect is provided to the advertisement. Typical examples of temporary advertisement campaigns are product introductions, temporary exhibitions, seasonal actions and elections. A temporary sign may be removed when the advertisement area is not sold or rented so that empty signs are prevented. Temporary signs further usually require “lighter” permits which may be handed out easier than permits for permanent signs.
An important aspect for temporary signs is to find a trade-off between economic factors as portability for transport and/or storage, time required for erecting the sign and/or putting up the display image, and more technical factors such as stability and robustness of the sign and public acceptability and aesthetics. For economic viability of temporary advertising, transportable signs usually are constructed from wooden boards and beams, with concrete blocks as counterweights. Another strategy, which has been initiated by the present applicant, is to use modular construction units such as used for scaffolding to erect a frame, and providing the frame with a board or cloth which carries the image to be displayed or which is to be provided with an advertisement image sheet e.g. a poster. Such previous transportable signs have limited aesthetic value, which prevents their use with some high level advertisements, e.g. high class art, cars and jewellery. They further may take significant time in manufacturing, erection and taking down. Further, the signs are not suitable for being transported in erected/assembled state, such that the signs themselves are not readily transportable.
A major concern for temporary signs is the construction of the sign for purposefully erecting it for a temporary campaign and deconstruction and storage of it afterwards. As a consequence, exchanging a display image tends to be complicated and thus time consuming and potentially dangerous for the operator. For working at an elevation higher than about 3 m, which is typically applicable for (putting up or exchanging) advertisement signs, recent laws forbid the use of ladders and instead prescribe the use of raised podia or cherry pickers. This significantly increases the time and costs for erecting and exploitation of temporary displays.